Self Adhering Membrane For Roofing Applications

ABSTRACT

A preformed, self adhering single ply roofing membrane including a water impermeable membrane; a pressure sensitive, hot melt adhesive adhered to one side of the water impermeable membrane, and a release liner on the side of the pressure sensitive, hot melt adhesive opposite of the water impermeable membrane.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No.10/153,132, filed May 22, 2002, the entire disclosure and contents ofwhich is hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to a self adhering membrane forroofing applications. More particularly, the present invention relatesto a performed self adhering single ply roofing membrane including apressure sensitive, hot melt adhesive adhered to one side of a waterimpermeable membrane.

2. Description of the Related Art

A roofing system generally includes a roof deck which is considered thestructural supporting surface of a building extending between thesurrounding exterior walls of the building. The roof deck may beconstructed from plywood, metal decking or concrete or any othersuitable material. Depending upon the construction, the roof deck mayextend over the surrounding exterior walls or the roof deck may stopshort of the exterior walls thereby forming a parapet wall, i.e., a lowretaining wall at the edge of the roof deck. If desired, the roofingsystem may also include an insulation barrier formed frompolyisocyanarate or any other suitable material applied over the roofdeck.

To make the roof deck and building weather resistant a single-plymembrane roof is installed over the roof deck. The single-ply membraneroof refers to a water impermeable single sheet of polymeric material.The membrane roof has heretofore been installed on the roof deck using avariety of different methods.

For example, the field or interior of the membrane roof may be held tothe roof deck by the use of ballast and/or penetrating ornon-penetrating fastener means as known in the art. An example of apenetrating fastener means for retaining the field of a membrane roofinstalled to a roof deck is by utilizing a plurality of small, circular,metal plates having a hole in the center and a roofing screw or othersuitable fastener. In order to anchor the membrane roof, the small,circular, metal plates are spaced apart in rows on the membrane roof andthe fastener is driven through the hole in each plate, the membraneroof, any insulation material and then into the roof deck. The metalplates are then covered by overlapping roof membrane. An example of anon-penetrating fastener means would include totally adhering the fieldof the membrane roof to the roof deck.

Although the many known variations for attaching a membrane roof to aroof deck have been proven to perform satisfactorily under certainconditions, further improvements on attaching a membrane roof to a roofdeck are desired.

The present invention is directed to a self adhering membrane forroofing applications. More particularly, the present invention relatesto a performed self adhering single ply roofing membrane including apressure sensitive, hot melt adhesive adhered to one side of a waterimpermeable membrane for application to a roofing deck and/or a parapetwall to form a water impermeable roofing membrane.

SUMMARY OF THE INVENTION

Briefly, the present invention relates to a preformed single ply roofingmembrane including a water impermeable membrane; a pressure sensitive,hot melt adhesive adhered to one side of the water impermeable membrane,wherein the pressure sensitive adhesive is free of a curing additive;and a release liner on the side of the pressure sensitive, hot meltadhesive opposite of the water impermeable membrane.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features of the present invention, as well as the advantagesderived therefrom, will become clear from the following detaileddescription made with reference to the drawings in which:

FIG. 1 is a cross sectional view of a preformed roofing membrane inaccordance with one aspect of the present invention;

FIG. 2 is a cross sectional view of a preformed roofing membrane inaccordance with another aspect of the present invention; and

FIG. 3 is a preformed roofing membrane in accordance with another aspectof the present invention.

DESCRIPTION FOR THE PREFERRED EMBODIMENT

Referring the figures, wherein like reference characters represent likeelements, there is shown a preformed self adhering roofing membrane 10in accordance with the present invention. As noted, the preformed selfadhering roofing membrane 10 includes a substrate sheet of waterimpermeable membrane 12, a pressure sensitive, hot melt adhesive 14adhered to one side of the water impermeable membrane, and a releaseliner 16 on the side of the pressure sensitive, hot melt adhesiveopposite of the water impermeable membrane.

The preformed self adhering roofing membrane 10 is securely attached toa roof substrate comprising a roof deck or parapet wall or curb to forma water impervious structure. The roof deck and/or parapet wall and/orcurb may be constructed from ply-wood, metal decking or concrete or anyother suitable material. On existing construction, the self adheringroof membrane 10 may be applied to a smooth asphalt top surface. Ifdesired, the roofing system may also include an insulation barrierformed from polyisocyanarate or any other suitable material applied overthe roof deck. A suitable primer may be used on the roof substratesurface to enhance the adhesion of the self adhering roof membrane.

The water impermeable membrane 12 of the preformed self adhering roofingmembrane 10 is formed of, for example, appropriate thermosettingmaterials and thermoplastic materials including polyvinyl chloride(PVC), thermoplastic olefin (TPO), polyethylene and polypropylene,chlorinated polyethylene (CPE), chloro-sulphinated polyethylene (CSPE)and polyisobutylene (PIB). Suitable thermosetting materials are EPDM,butyl rubber, and neoprene. These preformed self adhering single plyroofing membranes 10 may or may not include reinforcing meshes or scrimslocated intermediate layers 12 and 14 of the material forming the singleply roofing membrane. The water impermeable membrane 12 may range fromabout 0.020-0.090 inches thick, preferably 0.045-0.090 inches thick.

The water impermeable membrane 12 may range from about 6 inches-12 feetwide and of indeterminate length depending upon the intendedapplication. For example, when the preformed self adhering membrane 10is installed over the parapet wall or curb of a roofing installation thewater impermeable membrane ranges from 6 inches-3 feet in width andindeterminate in length as desired.

Adhered to one side of the water impermeable membrane 12 is the pressuresensitive, hot melt adhesive 14. The pressure sensitive, hot meltadhesive 14 is applied directly to the water impermeable membrane 12using most any suitable method well known in the art. For example, thepressure sensitive, hot melt adhesive 14 may be applied directly to thewater impermeable membrane 12 using a hot melt spray method or by usinga slot die method as well known in the art. It will be appreciated thatby applying the pressure sensitive, hot melt adhesive 14 directly to thewater impermeable membrane 12 better and more uniform bond strength maybe achieved in contrast to the use of a transfer adhesive.

Pressure sensitive, hot melt adhesives 14 in accordance with the presentinvention are solvent-free adhesives, that are characteristically solidat temperatures below 180 degrees F (° F.), are low viscosity fluidsabove 180° F., and rapidly set upon cooling. Exemplary of pressuresensitive hot melt adhesives are ethylene vinyl acetate (EVA)copolymers, compatible with paraffin; styrene-isoprene-styrene (SIS)copolymers; styrene-butadiene-styrene (SBS) copolymers; ethylene ethylacrylate copolymers (EEA); and polyurethane reactive (PUR), butyl orhalo-butyl rubbers, acrylic, ethylene propylene rubber (EPR), ethylenepropylene diene terpolymer rubber (EPDM) or styrene/butadiene rubbers(SBR) and styrene-ethylene-butene-styrene copolymers (SEBS) including avariety of tackifying resins, and optionally waxes, antioxidants,plasticizers, and other materials added to the adhesive formulation toenhance the polymer performance. In order to be considered useful forthe preformed singly ply roofing membrane 10 in accordance with thepresent invention, the pressure sensitive, hot melt adhesive 14 shouldnot include a curing or cross linking agent whereby the adhesivemaintains the desired thermoplastic properties. The pressure sensitivehot melt adhesive 14 must have a minimum peel strength of 0.5 pli at 70degees Fahrenheit as determined in accordance with ASTM D 3330 forroofing applications.

By way of a representative example only, a particular preferred pressuresensitive, hot melt adhesive 14 is PSA-3 Hot Melt Adhesive commerciallyavailable from ADCO Products, Inc.

The pressure sensitive, hot melt adhesive 14 thickness may range fromabout 0.004 inches to 0.015 inches.

A release liner 16 is applied against the pressure sensitive, hot meltadhesive 14 surface to prevent premature unwanted adhesion and, in thecase of rolls, ease of unwind without sticking to the backing. Therelease liner 16 is applied after the application of the pressuresensitive hot melt adhesive 14. For ease of application, the releaseliner 16 may be sliced into multiple sections to allow for portionedrelease of the liner from the water impermeable membrane duringapplication of the preformed self adhering membrane 10. The releaseliner 16 may comprise paper, or polyethylene, polypropylene or polyesterfilms of a type well known in the art.

As shown in FIG. 1, the water impermeable membrane 12; pressuresensitive, hot melt adhesive 14 and release liner 16 may beco-extensive. During application, two self adhering membranes 10 may bejoined by positioning the membranes in overlapping relation and thenheat welding or adhesively bonding the overlapping edges or if themembranes are butted together, a cover cap may be adhered or hot airwelded over the seam. In alternate embodiment, as shown in FIG. 2, therelease liner 16 and pressure sensitive hot melt adhesive 14 may becoextensive and the combined release liner 16 and pressure sensitiveadhesive 14 may be spaced from at least one marginal edge of the waterimpermeable membrane 12 to provide a free edge of water impermeablemembrane. The free edge of water impermeable membrane 12 may overlap anadjacent water impermeable membrane and either be hot air welded orsolvent based adhered or tape adhered to the overlapped membranedepending upon the type of water impermeable membrane to be joined. Inyet another embodiment as shown in FIG. 3, the pressure sensitive, hotmelt adhesive 14 and the release liner 16 may be coextensive and thecombined release liner and pressure sensitive adhesive may be spacedfrom at least one marginal edge of the water impermeable membrane. Thefree edge of water impermeable membrane includes a cured, pressuresensitive adhesive composition 18 including a release liner as describedin U.S. Pat. No. 5,242,727, incorporated herein by reference. Thepreformed self adhering membranes 10 may be joined together byoverlapping the cured pressure sensitive adhesive 18 and the waterimpermeable membrane 12 and then removing a release liner 20 andpressing adhesive 18 of one membrane against the other membrane.

The preformed self adhering membrane 10 as shown in the figures isjoined to the roof substrate by removing the release liner 16 and thenpressing the pressure sensitive, hot melt adhesive 14 directly to theroof substrate.

The patents and documents described herein are hereby incorporated byreference.

Having described presently preferred embodiments of the invention, theinvention may be otherwise embodied within the scope of the appendedclaims.

While the invention has been specifically described in connection withcertain specific embodiments thereof, it is to be understood that thisis by way of illustration and not of limitation, and the scope of theappended claims should be construed as broadly as the prior art willpermit.

1-17. (canceled)
 18. A membrane product comprising: a water impermeablemembrane; and a pressure sensitive adhesive adhered to one side of thewater impermeable membrane, wherein the adhesive is in direct contactwith at least a portion of the water impermeable membrane, wherein theadhesive is free of a curing additive, wherein the adhesive has athickness of 0.015 inches or less, wherein the membrane product isadhered to a portion of a building by the adhesive, wherein the membraneproduct is self adhering, and wherein the water impermeable membrane isthe outermost layer of the membrane product relative to the building.19. The membrane product of claim 18, wherein the adhesive has athickness of 0.004 to 0.015 inches
 20. The membrane product of claim 18,wherein the membrane is comprised of a thermoplastic material.
 21. Themembrane product of claim 18, wherein the membrane is comprised of athermosetting material.
 22. The membrane product of claim 21, whereinthe thermosetting material is selected from EPDM, butyl rubber, andneoprene.
 23. The membrane product of claim 18, wherein the firstadhesive is a solvent-free adhesive.
 24. The membrane product of claim18, wherein the first adhesive is selected from ethylene vinyl acetatecopolymers, compatible with paraffin; styrene-isoprene-styrenecopolymers; styrene-butadiene-styrene copolymers; ethylene ethylacrylate copolymers; and polyurethane reactive, butyl or halo-butylrubbers, acrylic, ethylene propylene rubber (EPR), ethylene propylenediene terpolymer rubber (EPDM) or styrene/butadiene rubbers (SBR) andstyrene-ethylene-butene-styrene copolymers.
 25. The membrane product ofclaim 18, wherein the water impermeable membrane is single ply.
 26. Themembrane product of claim 18, wherein the membrane product is adhered toa roof deck.
 27. A membrane product consisting essentially of: a waterimpermeable membrane; and a pressure sensitive adhesive adhered to oneside of the water impermeable membrane, wherein the adhesive is indirect contact with at least a portion of the water impermeablemembrane, wherein the adhesive is free of a curing additive, wherein thefirst adhesive has a thickness of 0.015 inches or less, wherein themembrane product is adhered to a portion of a building by the firstadhesive, and wherein the membrane product is self adhering.
 28. Themembrane product of claim 27, wherein the adhesive has a thickness of0.004 to 0.015 inches
 29. The membrane product of claim 27, wherein thewater impermeable membrane is the outermost layer of the membraneproduct relative to the building.
 30. The membrane product of claim 27,wherein the membrane is comprised of a thermoplastic material.
 31. Themembrane product of claim 27, wherein the membrane is comprised of athermosetting material.
 32. The membrane product of claim 31, whereinthe thermosetting material is selected from EPDM, butyl rubber, andneoprene.
 33. The membrane product of claim 27, wherein the adhesive isa solvent-free adhesive.
 34. The membrane product of claim 27, whereinthe first adhesive is selected from ethylene vinyl acetate copolymers,compatible with paraffin; styrene-isoprene-styrene copolymers;styrene-butadiene-styrene copolymers; ethylene ethyl acrylatecopolymers; and polyurethane reactive, butyl or halo-butyl rubbers,acrylic, ethylene propylene rubber (EPR), ethylene propylene dieneterpolymer rubber (EPDM) or styrene/butadiene rubbers (SBR) andstyrene-ethylene-butene-styrene copolymers.
 35. The membrane product ofclaim 27, wherein the water impermeable membrane is single ply.
 36. Themembrane product of claim 27, wherein the membrane product is adhered toa roof deck.